1. Field of the Invention
The invention relates to a circuit for processing an audio signal, comprising:
an input for receiving the audio signal and an output for supplying an output signal, PA1 selecting means coupled to the input for selecting a frequency band of the audio signal, PA1 harmonics generator coupled to the selecting means for generating harmonics of the selected signal, PA1 adding means coupled to the input as well as to the harmonics generator for supplying a sum of the input signal and the generated harmonics to the output. PA1 selecting a frequency band of the audio signal, PA1 generating harmonics of the selected signal, PA1 supplying a sum of the audio signal and the generated harmonics. PA1 detecting means for detecting a level of at least a part of the spectrum of the audio signal including the selected frequency band, and PA1 scaling means for scaling the generated harmonics in response to said level. PA1 a further selecting means coupled to the input, having a selection characteristic for selecting a part of the input signal in frequency adjacent to the selected signal of the selecting means, PA1 a further harmonics generator coupled to the further selecting means for generating harmonics of the signal selected by the further selecting means, PA1 further detecting means coupled to the further selecting means for detecting a level of the by the further selecting means selected signal, and PA1 further scaling means for scaling the by the further harmonics generator generated harmonics in response to said level.
The invention also relates to an audio reproduction system comprising such a circuit.
The invention further relates to a method for processing an audio signal, comprising the steps of:
2. Description of the Related Art
A circuit according to the preamble is known from European Patent Application EP-A 546 619. In the known circuit, a low frequency band of an input signal is selected and supplied to a harmonics generator for generating harmonics of the selected signal. In this way, low-frequency perception of the audio signal is improved upon. In the known circuit a full-wave rectifier is used as harmonics generator. A drawback of the full-wave rectifier is that it generates only even harmonics.